Normally, the wood boiler is plumbed to a heat exchanger (see drawing above). As you can see, this allows the boiler to heat a tank of potable water, which in turn can provide domestic hot water AND floor heating (in an “open” or “closed” configuration).

The cap on the air eliminator is closed when it is tightened (clockwise) and opened when the cap is backed off (counterclockwise) a few turns, so that daylight is visible through the slit in the cap,…The air eliminator cap may be removed if you wish, but is not necessary.  When filling the system with liquid, the air eliminator’s cap can be either in the open or closed position.  Pressure testing the system with air requires that cap to be closed so that it doesn’t release air ,…as that is it’s purpose. It is most important that the cap is opened for the duration of the system’s operation.

Fortunately, few words are needed to describe this replacement system — simple and elegant.  In the hands of masterful professionals like DC Cheek Heating and Cooling, to say nothing of do-it-yourselfers working on their own homes, Radiant Floor Company’s heating packages become art.

Water Pressure Reducing Valves have been described as "life-of-mortgage" products, because historically a malfunctioning water pressure reducing valve is not replaced but simply cleaned or repaired via an inexpensive service kit. Design-wise, it is similar to the kitchen faucet in that dirt or foreign matter on the seating area can cause problems and actually it is no more difficult to repair a water pressure reducing valve than it is to fix the kitchen faucet.

A mixing valve is pre-installed in this type of manifold. The baseboard or cast iron radiator zones, for example, receive super hot water straight from the heat source. The much cooler radiant floor zones receive tempered water from the “mix” port of the mixing valve.  The schematic below illustrates this approach.

For a single radiant zone coming off an existing, conventional boiler, this “Radiant Ready J” model includes a mixing valve to temper the 180-degree boiler water down to the much lower 120-135 degree range, ideal for in-floor systems.

The last time that you take the filter out of the water heater to clean it,  and it’s clean,….. you may remove it, as it is designed to simply “Snap off” from the black cap, this will reduce head pressure and minimize any chance of the a-fore mentioned.  The inline strainer is to stay in the system.

Your expansion tank is pre-charged and should not need any pressure.   If your pressure is dropping below the 15 psi, it is an indication of air still trapped in your system,…. Air is the WORST thing that can happen to any (Hydronic) Radiant heating system.     Follow this link, https://www.radiantcompany.com/details/fill/ for information on filling and purging your Closed Radiant heating system.

Reducing the pressure from 100 lbs. to 50 lbs.will result in a savings of approximately 1/3 because 1/3 less water flows at this lower pressure. Remember, there is more "push" behind the water at 100 lbs. than at 50 lbs. and most of this water is wasted. Almost twice as much water flows at 150 lbs. than 50 lbs., most of which is wasted. Moderate savings would result if your supply pressure was 65 lbs. However, even at this lower pressure, savings with a water pressure reducing valves would be 20%.

The photo above is our “Radiant Ready A/T” single zone Closed System for use with an on-demand water heater. This pre-assembled, panel system comes right out of the box just as you see it here, including pump, pre-wired controller, expansion tank, air eliminator, in-line thermometers, and various gauges and valves. The entire package is pressure tested against leaks and as few as four solder connections can tie it into your system.

As air leaves a system, the pressure will drop. When the Radiant heating system heats up, the pressure will increase, but when it cools, it will drop in pressure…..   We recommend that you maintain at least 15 psi when the system is cold. When a heated system’s pressure is near 0,… and then cools,… it will create a NEGATIVE pressure… Thus creating a VACUUM, this will suck air into the system! The Closed system expansion tank is pre-charged and should not need any pressure. If pressure is dropping below the 15 psi, it is an indication of air still trapped in your system,…. Air is the WORST thing that can happen to any (Hydronic) Radiant heating system.  Follow this link, https://www.radiantcompany.com/details/fill/ for information on filling and purging your Closed Radiant heating system. We recommend Propylene Glycol (not automotive, Ethylene Glycol) antifreeze.

1) the pipe from the wood boiler to the house can be buried in a shallow trench (normally about 1 ft.), saving a lot of labor and/or expensive excavation costs (obviously, with constantly circulating hot water in the supply and return lines, freezing is impossible, even in a trench well above the frost line), and

Also called water pressure regulators, water pressure reducing valves are compact, inexpensive valves that perform two functions: They automatically reduce the high incoming water pressure from the city mains to provide a lower, more functional pressure for distribution in the home. They "regulate" by maintaining a set pressure in the home usually 50 lbs. thereby insuring that the home piping and appliances operate under a safe, more moderate, but satisfactory pressure.

Yes. They are required by the Federal Housing Administration, the regional plumbing codes such as IPC and UPC, and numerous city and state codes. The requirement is that whenever the city main water pressure exceeds 80 lbs., a water pressure reducing valve must be installed. However, because of the recently acknowledged advantages of water pressure reducing valves conservation wise, they could be economically installed even where supply pressures are in the vicinity of 60 lbs. because of the water and energy saving benefits they can provide.

Some outdoor wood boilers are either multi-fuel systems (i.e. they can burn wood and gas or oil) or they have a built-in heat exchanger coil to supply domestic hot water. With this style of boiler the separate storage/back-up tank is not needed and the radiant floor can be run directly from the boiler.

Many customers, especially in rural areas, are installing outdoor wood boilers and using them in conjunction with radiant floor heating. Normally, these boilers, via a heat exchanger, are plumbed into a storage/back-up tank that can take over the task of heating the water when the winter fatigued homeowner flies off to the Caribbean and becomes unavailable to throw wood into the boiler.

A heat source like an electric boiler (“Electro” boiler shown above) can be thermostatically controlled very much like a conventional tank-type water heater to send low temperature water (120-135-degrees) to the floor. However, if you are using a conventional boiler (185-degree water) for a heat source, a mixing valve is required. See below.

Water pressure reducing valves are commonly installed at the meter in residential, commercial, and industrial buildings. This location is desirable because it then controls the water pressure flowing to all appliances and outlets within the building and provides an inexpensive means of supplying lower, more functional water pressure to outlets and appliances.

This approach utilizes a dedicated heat source for the radiant floor. The fluid in a closed system is re-circulated around and around in a completely closed loop. There is no connection whatsoever to the domestic water supply. The main advantage to this system lies in the fact that, being closed, anti-freeze instead of water can be used as the heat transfer medium. The percentage of anti-freeze (Propylene Glycol) is determined by the type of heat source (on-demand heater or tank-type) and by the guidelines listed on the anti-freeze container.

A typical family of four uses an average of 255 gallons of water each day for interior plumbing. This is broken down by: dishwashing - 15 gallons; cooking/drinking - 12 gallons; utility sink - 5 gallons laundry - 35 gallons; bathing - 80 gallons; bathroom sink - 8 gallons; toilet - 100 gallons. When you multiply this by a year, typical family usage totals 93,000 gallons of water. If you have teenagers, you would undoubtedly use more than the above averages.

High water pressure, which is generally considered anything above 60 lbs., has some advantage, such as in firefighting systems. However, in the home plumbing system, it can be damaging because water can erode or wear away many materials. A big "push" in home plumbing can also cause leaking water heaters, banging water pipes, dripping faucets, dishwasher, and clothes washer noise and breakdown, or leaking water pipes. Water flowing at a rate in excess of that necessary to satisfy normal fixture or appliance demands becomes damaging, wasteful, and reduces the life expectancy of equipment in the system. But, probably most important to the average homeowner is that it can add to the cost of water, energy, and waste water bills.

As mentioned before, 1/3 less water flows 50 lbs. than at 100 lbs. Therefore, when you reduce the city main pressure to a more moderate pressure of 50 lbs., you can look forward to conserving up to 1/3, or more, of the water previously consumed and this will be reflected on your water bills.

Regardless of which radiant heating system you choose, be it Open, Closed Or heat exchanger, or type of fuel source you require, Propane, Natural gas, Electric or Oil,…Radiant Floor company has you covered!!!

Several years ago when Grundfos introduced the revolutionary “ALPHA” series of hydronic circulators to the US market, we were amazed by two things: 1) the incredible efficiency and energy saving potential of the ALPHA, and 2) by their high cost.

A high rise office building in Chicago was designed using water conservation products which resulted in savings of more than 3,000,000 gallons of water per year. This is significant in that the municipal water utility did not have to pump the extra gallons, the water purification plant didn't have to treat it, while the building itself saved on pumping of 3,000,000 gallons, resulting in significant savings in energy by conserving hot water. Also, there were further savings by the fact that 3,000,000 gallons of water, or the normal portion thereof, did not have to be distributed to the wastewater system and consequently the water treatment plant did not have to retreat this water. The heating of water takes energy and it should also be remembered that "pumping" water from one place to another also requires a considerable amount of energy.

This schematic applies to the above mentioned types of outdoor wood boilers. Just remember to bury the supply and return lines from your boiler below the frost line. Here’s why…

Since most conventional boilers are designed to produce super hot water (185-degrees), Radiant Floor Company builds what we call “split” manifolds for multiple zone “closed” systems that use radiant floor heat in combination with standard baseboard radiators, fan coils, cast iron radiators, or any other hydronic heating device that requires super hot temperatures.

If you have an outdoor wood boiler, and for whatever reason you need to use antifreeze in the radiant floor system, the following schematic should be very helpful.

A rule of thumb is: If you hear banging pipes in your home or observe water splashing in your sink, you probably have excessive pressure. However, for a precise reading, your local plumbing contractor or utility can test your pressure with a gauge.

A utility transfer pump — NOT a sump pump is to be used when back flushing a unit and when filling and purging a Closed system utilizing an antifreeze mixture. We recommend a powerful utility pump like the Wayne EC-50, or the Wayne PC-4, or an equivalent pump like the Utilitech .5 HP Cast Iron Transfer Pump, all of which can generate up to 45-psi.   The following link https://www.waynepumps.com/solution-center/utility-pumps-transfer/pc4  are specifications for pump (Model # PC4).

If you have three zones, for example, close the ball valves below the pumps for zones 2 and 3, and focus your water flow on Zone #1.

EVERY heating unit that Radiant Floor company recommends and offers is “DESIGNED & RATED FOR SPACE HEATING”! These units are not your “typical” water heaters, so don’t let the compact size fool you! All of our heating units are manufactured to an industry standard of quality and reliability.

Determine how much antifreeze your system requires by adding the total amount of fluid in the tubing (2.7 gallons per 100 ft. of 7/8″ Pex) plus the volume of water in the Heat source (water heater or boiler).

Let’s be honest. There aren’t enough words in the English language to describe the problems with the above installation, or the shock of encountering it. If the guys at Cheek’s Heating were lucky, it didn’t bite them when they touched it.

Put a stopper in your sink or use a dishpan when you wash dishes. Washing with running water uses 30 gallons per meal. Keep a bottle of drinking water in the refrigerator running the water from the faucet until cold will waste a gallon. Wait until you have a full nine-pound wash before you run your washing machine. The average machine uses 50 gallons per load. Turn the hot water off while you shave, and turn the cold water off while you brush your teeth. Shaving with a running faucet uses about 20 gallons. Take showers instead of baths. The usual bath requires 36 gallons, the usual shower, only 25. Ten gallons is enough for a shower if you turn it off while you lather. Don't use the toilet bowl to dispose of cigarette ashes, facial tissues, and other materials. A normal flush requires 8 gallons. Use dishwasher only when completely full. Fix dripping faucets promptly. Nearly two gallons can be wasted per day of dripping. Running toilets can waste four gallons per hour. Keep them in good repair. THINK before you turn on the tap.

There’s not a lot maintenance for our Radiant heating systems but to clean a filter in the water heater and maintain system pressure.  Follow this link, https://www.radiantcompany.com/details/fill/ and scroll down half the page for information on cleaning the filter & strainer for your Closed Radiant heating system.

Determine what percentage of anti-freeze to water mixture is recommended by the manufacture of the heat source. Ratios can vary. Some manufacturers recommend anywhere from 20%, 30 % anti-freeze, other’s 50%. The proper mix is also influenced by the degree of low temperature you wish to protect against.  Some antifreeze comes “Pre-diluted” Be sure to check before purchasing.

The down side is two heat sources. All water heaters waste heat energy, even when the burner is off and the unit is sitting idle between heating cycles. Granted, the unit dedicated to heating the floor only wastes heat during the winter months. But standby losses for six months out of every year can add up. The other consideration is efficiency. Two low or moderately efficient water heaters are much more costly to run than one high-efficiency unit.

The water from the boiler to this heat exchanger flows 24 hours a day in a closed loop, making the heat exchanger “continuously active” (i.e. always hot). Whenever needed, the storage tank draws heat from the heat exchanger and maintains a constant tank temperature. The advantages of a continuously active heat exchanger loop are twofold:

If you are you using antifreeze in your system, we recommend Propylene Glycol (not automotive Ethylene Glycol) antifreeze.

You don’t have to use antifreeze, in fact a Radiant system is most efficient when using water. BUT “peace of mind” has it’s worth! If you feel you want or need to use antifreeze, continue below: We recommend Propylene Glycol (not automotive Ethylene Glycol) antifreeze.  Determine how much antifreeze your system requires by adding the total amount of fluid in the tubing (2.7 gallons per 100 ft. of 7/8″ Pex …  1.9 gallons per 100′ 3/4″ pex… 1.3 gallons per 100ft of 1/2″ Pex) plus the volume of water in the Heat source (water heater or boiler).

Certainly. The water pressure reducing valve is the hub of a conservation program; but you should also consider flow control devices, low-flush toilets, improved water heating equipment, and better disciplined habits by the user. However, if none of these devices were installed, the water pressure reducing valve would still serve to contribute important and significant savings in energy and water, resulting in average savings of anywhere from $50 to $150 per year, or more depending on your local rates.

When we can save 1/3 of the water previously consumed, this also represents a similar saving of water which will not be going into the sewer system where it has to be treated. Water does not evaporate after we use it and it has to be piped to the wastewater system. Many sewer bill taxes or surcharges are based on the amount of water you use, with the assumption that this water is going into the wastewater system. This is billed to you as a sewer surcharge and, in many cases, the sewer tax can equal the water cost. Therefore, when water pressure reducing valves save 1/3 of the metered water, they also contribute to saving up to 1/3 of the wastewater, which is extremely important because it benefits both the user, by a lower sewer bill, and the community, as this is water they do not have to treat.

Yes. In 1971 the Washington Suburban Sanitary Commission conducted a test program in 2,400 dwelling units that has attracted widespread interest from more than 40 states and various foreign countries. One of the devices used in their conservation study was a water pressure reducing valves. It is interesting to note that their report concluded that in test locations using water pressure reducing valves, there was a water consumption reduction of 30% in October and November and 37% in December.

Most people have considered water pressure reducing valves as pressure controls because, as described in the foregoing, they are used to protect appliances and piping from the effects of high water pressure. However, because of water and energy shortage in addition to cost problems, water pressure reducing valves have become increasingly more important because they automatically provide the advantage of conserving water and energy.

There are, of course, different styles of water pressure reducing valves and various installation charges throughout the country. An estimate can be obtained from your local qualified plumbing contractor. To determine how much you, as an individual, would be saving, it would be necessary to consider the factors in question 17, in comparing with your current water and energy bills.

The easiest way would be to call your local qualified plumbing contractor who can provide you with an estimate and also advise of the various types of water pressure reducing valves available and the one best suited for your home. Although water pressure reducing valves are fairly simple to install and could be a do-it-yourself project, there are some laws which mandate that only a licensed plumbing contractor be permitted to work on the home potable drinking water system for health and safety purposes.

The Environmental Protection Agency estimate that 30% of the water used in households is heated and, in order to heat this water, it takes energy. If a water pressure reducing valve can reduce consumption by 1/3, we automatically cut down on the amount of hot water we're using in lavatories and showers and, therefore, we automatically reduce the amount of energy required to heat that load. Thus, it can be easily seen that water conservation has a direct relationship to energy conservation. An average shower, for example, costs approximately 17 cents in energy and a shave with the faucet running cost 10 cents in energy.

NOISE: A rumbling noise coming from the on demand water heater is (most likely) liquid boiling as it passes through the heat ex-changer in the water heater.  This is due to liquid traveling too slowly through the unit. This reduced flow is caused by either a constriction or obstruction in the system’s plumbing. A dirty filter and/or strainer,  Improper piping, sticky, obstructed or clogged check valve or mixing valve, mineral build up, (a result of hard water), improper pump speed setting, too much antifreeze-if applicable (closed system) or the water heater temperature set too high. The culmination of any,…(or) all of these can lead to a noisy heating unit!

Closed systems are often used in second homes or primary residences in areas prone to long power outages. If freeze protection is an issue, than a closed system with anti-freeze is a good idea.

The hotter baseboard radiator returns enter the manifold AFTER the “cold” supply pipe to the mixing valve. In this way, the cooler radiant floor returns can provide ideal tempering water.  Radiant Floor Company can customize a Zone Manifold to suit any application. In this case, one leg on the left side of the manifold feeds a baseboard zone with straight 180 degree boiler water. The two legs to the right of the mixing valve supply the radiant tubing with boiler water that has been tempered by the return water down to 125 degrees.

This means, in essence, that a boiler sized to provide X number of BTU’s of heating capacity is now providing considerably less than it’s design rating. Because when one of the heating zones calls for heat, a circulator pump comes on, water again flows through the boiler stirring the hotter and cooler water together, and suddenly 185 degree water becomes 145 degree water. This can really matter in a marginally sized system.

When a fixture in a home is opened and water flows from it, it is because the water is "pushed." This "push" is pressure. The speed at which water flows from the opened outlet depends on the amount of "push" or pressure which exists at that time in the system. In short, the higher the pressure, the stronger the "push" behind the water.

Yes, and water hammer is very simply the noise generated by the shocks of high-speed water flowing in a pipe when a fixture is suddenly closed. The sudden stoppage causes a "bounce back" of the water and is called water hammer, causing banging pipes, noisy systems, and damage to appliances. It might be comparable to driving your car at slow speed into a wall where the effect is negligible. However, if you drove the car at a much higher speed, the impact would be greater and, consequently, so would the bounce back or shock. Another description of the water hammer effect of high water pressure can be easily demonstrated. First, walk around a sharp corner and then run around the same corner. We can equate walking around the corner to a lower, more functional, controlled water pressure. However, when you run around the corner, the momentum forces your body to swing in a wider, uncontrolled arc. This principle is based on the fact that moving objects, and this includes water, tend to move in a straight line. They resist changes in direction. Therefore, in a home where the piping has many changes in direction, water hammer shock can be limited by reducing the water pressure.

If Zone #1 has multiple circuits of tubing, each circuit will have a ball valve on the supply side of the loop manifold, close off all the circuits of Zone #1 except the first one and channel the water into that first circuit.  When circuit #1 of Zone #1 has been purged, then close off circuit #1 and open circuit #2. Repeat this process for every circuit in every zone.

Determine how much antifreeze your system requires by adding the total amount of fluid in the tubing (2.7 gallons per 100 ft. of 7/8″ Pex …1.9 gallons per 100′ 3/4″ pex… 1.3 gallons per 100ft of 1/2″ Pex) plus the volume of water in the Heat source (water heater or boiler). Radiant Floor Company includes this information on your worksheet.

Yes, and they can effectively be installed on showerheads, fixtures, and tankless heater boilers. Many showerheads, for example, apply water at a rate of 6gpm. Applying a 3gpm flow restrictor will cut the flow in half providing savings in water and energy. It should be remembered however that their capacity is based on a "fixed" supply pressure like 50 lbs. and operating under a higher pressure will permit greater flow. That's why we say a water pressure reducing valve is the "hub" of a program because it maintains a constant pressure throughout the home, thereby improving the performance of flow-restricting devices.

We have previously described the effects of high water pressure on piping and appliances. When having these appliances work under a lower pressure, their life expectancy will be much longer and will also cut down on service calls caused by problems with dish washers and clothes washers, leaky water heaters, leaking water pipes, and the potential water damage which could be resulting.

Nevertheless, we were excited enough to invest in several ALPHA pumps for testing purposes and we’re convinced that, if anything, the Grundfos estimates on cost savings are conservative.  Now, four years later, the cost of the ALPHA series pumps has dropped dramatically and the price is now within the range of many conventional radiant circulators. As a result, we’re incorporating ALPHA circulators into our radiant system designs whenever possible so our customers can enjoy 50-75% cost savings while running their pumps.

Very large radiant systems require Primary/Secondary plumbing. If you’re interested in the fine details of this plumbing approach, you can find more information in the Heat  Sources / On-demand Water Heaters / Primary/Secondary plumbing section of this website. The photo below illustrates a beautiful, real-world application of this method.

This customer chose to use Unistrut channel to mount his “Closed” Radiant Ready system instead of the plywood board included in the kit, but the result is the same — a clean, compact, beautiful do-it-yourself installation. Note the addition of a mixing valve (the silver, three-way valve with the gray knob) to this system. This gives the customer a more precise control of the system’s water temperature.

2) by keeping the water in the boiler constantly circulating, stratification is eliminated. In other words, without constant flow through the boiler, the water at the top of the water jacket gets VERY hot, and the water at the bottom stays much cooler. And since most boilers have water jackets containing several hundred gallons of water, 50% of the water in the boiler could be 185 degrees (the temperature at which the boiler damper shuts off the air supply and sends the boiler into resting mode) and the other 50% could be considerably cooler.

These highly efficient heaters are built with Radiant heating in mind. We offer units that will heat both your Radiant (space heating) and domestic hot water.

One day we received a call from an HVAC contractor, DC Cheek Heating and Cooling, down in Cumming, Georgia.  Being a company devoted to integrity and quality, they accepted the challenge of converting an existing horror show of plumbing parts (somebody’s misguided version of a “closed/heat exchanger system”), to a Radiant Floor Company “Open System”, using a Takagi, on-demand water heater. They were kind enough to send us “before” and “after” photos.

Filling and purging a Radiant heating system is a critical process! As air leaves a system the pressure will drop.   When your Radiant heating system heats up, the pressure will increase, but when it cools, it will drop in pressure…..   We recommend that you maintain at least 15 psi when the system is cold.    When a heated system’s pressure is near 0,… and then cools,… it will create a NEGATIVE pressure… Thus creating a VACUUM, this will suck air into the system!

Determine what percentage of anti-freeze to water mixture is recommended by the manufacture of the heat source. Ratios can vary. Some manufacturers recommend anywhere from 20%, 30 % anti-freeze, other’s 50%. The proper mix is also influenced by the degree of low temperature you wish to protect against. Some antifreeze comes “Pre-diluted” Be sure to check before purchasing. “ALWAYS PRE-MIX YOUR ANTIFREEZE BEFORE PUMPING IT INTO YOUR SYSTEM”!

The following drawing outlines the copper fittings necessary to connect various sizes of Expansion and Purge Kits to the Zone Manifold. These fittings and a hard copy of this drawing are included with every Closed and Heat Exchanger system.

If you are not using house pressure (from a hose etc.) then you may use a utility transfer pump, to pump the liquid into your system.

So, the point is, if you want to run a radiant system directly off your wood boiler, always bury your supply and return pipes below the frost line. As explained above, the water to and from your house will only be flowing when a radiant zone calls for heat. And because many outdoor wood boilers are 30 to 100 feet away from the home, a lot of water can be sitting in a cold (though admittedly insulated) trench for a long time. If that trench is above the frost line, you could have serious trouble. Multi-fuel wood boiler, or boiler with built-in heat exchanger for domestic hot water. The lines to and from the boiler must be buried below the frost line.

There’s not a lot maintenance for our Radiant heating systems but to clean a filter in the water heater and maintain system pressure.  A system’s filter and strainer will become dirtiest when filling, purging and start up, as the impurities in the system will flow through to the strainer and filter. Flux is a solid (greasy /pasty) form when cold and liquefies when heated, particulates will loosen and move along to the strainer and filter.

An average savings would be from $50 to $150 per year, probably much higher. Based on the fact that 1/3 less water flows at 50 lbs. than 100 lbs., you can expect to save up to 1/3 of the water previously consumed. As a typical family of four uses 90,000 gallons per year, that would mean a savings of approximately 30,000 gallons of water. The higher the pressure, the higher the savings. Lower pressures result in less savings. (Your water Company can provide the rate.) Remember also, however, that 1/3 of the water used in homes is heated; so 1/3 of the 30,000 gallons of water saved divided by 2 to reflect a cold water mixing factor would mean a savings in heating up to 5,000 gallons of hot water per year. If you figure 4 cents to heat a gallon of water, the savings would be $200.00. You can also figure on a savings in your sewer surcharge bill, since most of the 30,000 gallons of water saved will not be going into the wastewater system, therefore, you will not be assessed on that. (Contact your local authority for any assessment charges.) You would also have to figure the savings, generated by not having to have appliances repaired or replaced more frequently. This is a nebulous figure but, based on your own experience over the past years, you could look for a reduction in the frequency of maintenance and certainly for an improved performance by these appliances.